Commit | Line | Data |
---|---|---|
16444a8a | 1 | # |
606576ce SR |
2 | # Architectures that offer an FUNCTION_TRACER implementation should |
3 | # select HAVE_FUNCTION_TRACER: | |
16444a8a | 4 | # |
2a3a4f66 FW |
5 | |
6 | config NOP_TRACER | |
7 | bool | |
8 | ||
606576ce | 9 | config HAVE_FUNCTION_TRACER |
16444a8a | 10 | bool |
bc0c38d1 | 11 | |
677aa9f7 SR |
12 | config HAVE_DYNAMIC_FTRACE |
13 | bool | |
14 | ||
8da3821b SR |
15 | config HAVE_FTRACE_MCOUNT_RECORD |
16 | bool | |
17 | ||
352ad25a SR |
18 | config TRACER_MAX_TRACE |
19 | bool | |
20 | ||
7a8e76a3 SR |
21 | config RING_BUFFER |
22 | bool | |
23 | ||
bc0c38d1 SR |
24 | config TRACING |
25 | bool | |
26 | select DEBUG_FS | |
7a8e76a3 | 27 | select RING_BUFFER |
c2c80529 | 28 | select STACKTRACE if STACKTRACE_SUPPORT |
5f87f112 | 29 | select TRACEPOINTS |
f3384b28 | 30 | select NOP_TRACER |
bc0c38d1 | 31 | |
17d80fd0 PZ |
32 | menu "Tracers" |
33 | ||
606576ce | 34 | config FUNCTION_TRACER |
1b29b018 | 35 | bool "Kernel Function Tracer" |
606576ce | 36 | depends on HAVE_FUNCTION_TRACER |
d3ee6d99 | 37 | depends on DEBUG_KERNEL |
1b29b018 SR |
38 | select FRAME_POINTER |
39 | select TRACING | |
35e8e302 | 40 | select CONTEXT_SWITCH_TRACER |
1b29b018 SR |
41 | help |
42 | Enable the kernel to trace every kernel function. This is done | |
43 | by using a compiler feature to insert a small, 5-byte No-Operation | |
44 | instruction to the beginning of every kernel function, which NOP | |
45 | sequence is then dynamically patched into a tracer call when | |
46 | tracing is enabled by the administrator. If it's runtime disabled | |
47 | (the bootup default), then the overhead of the instructions is very | |
48 | small and not measurable even in micro-benchmarks. | |
35e8e302 | 49 | |
81d68a96 SR |
50 | config IRQSOFF_TRACER |
51 | bool "Interrupts-off Latency Tracer" | |
52 | default n | |
53 | depends on TRACE_IRQFLAGS_SUPPORT | |
54 | depends on GENERIC_TIME | |
d3ee6d99 | 55 | depends on DEBUG_KERNEL |
81d68a96 SR |
56 | select TRACE_IRQFLAGS |
57 | select TRACING | |
58 | select TRACER_MAX_TRACE | |
59 | help | |
60 | This option measures the time spent in irqs-off critical | |
61 | sections, with microsecond accuracy. | |
62 | ||
63 | The default measurement method is a maximum search, which is | |
64 | disabled by default and can be runtime (re-)started | |
65 | via: | |
66 | ||
67 | echo 0 > /debugfs/tracing/tracing_max_latency | |
68 | ||
6cd8a4bb SR |
69 | (Note that kernel size and overhead increases with this option |
70 | enabled. This option and the preempt-off timing option can be | |
71 | used together or separately.) | |
72 | ||
73 | config PREEMPT_TRACER | |
74 | bool "Preemption-off Latency Tracer" | |
75 | default n | |
76 | depends on GENERIC_TIME | |
77 | depends on PREEMPT | |
d3ee6d99 | 78 | depends on DEBUG_KERNEL |
6cd8a4bb SR |
79 | select TRACING |
80 | select TRACER_MAX_TRACE | |
81 | help | |
82 | This option measures the time spent in preemption off critical | |
83 | sections, with microsecond accuracy. | |
84 | ||
85 | The default measurement method is a maximum search, which is | |
86 | disabled by default and can be runtime (re-)started | |
87 | via: | |
88 | ||
89 | echo 0 > /debugfs/tracing/tracing_max_latency | |
90 | ||
91 | (Note that kernel size and overhead increases with this option | |
92 | enabled. This option and the irqs-off timing option can be | |
93 | used together or separately.) | |
94 | ||
f06c3810 IM |
95 | config SYSPROF_TRACER |
96 | bool "Sysprof Tracer" | |
4d2df795 | 97 | depends on X86 |
f06c3810 IM |
98 | select TRACING |
99 | help | |
100 | This tracer provides the trace needed by the 'Sysprof' userspace | |
101 | tool. | |
102 | ||
352ad25a SR |
103 | config SCHED_TRACER |
104 | bool "Scheduling Latency Tracer" | |
d3ee6d99 | 105 | depends on DEBUG_KERNEL |
352ad25a SR |
106 | select TRACING |
107 | select CONTEXT_SWITCH_TRACER | |
108 | select TRACER_MAX_TRACE | |
109 | help | |
110 | This tracer tracks the latency of the highest priority task | |
111 | to be scheduled in, starting from the point it has woken up. | |
112 | ||
35e8e302 SR |
113 | config CONTEXT_SWITCH_TRACER |
114 | bool "Trace process context switches" | |
d3ee6d99 | 115 | depends on DEBUG_KERNEL |
35e8e302 SR |
116 | select TRACING |
117 | select MARKERS | |
118 | help | |
119 | This tracer gets called from the context switch and records | |
120 | all switching of tasks. | |
121 | ||
1f5c2abb FW |
122 | config BOOT_TRACER |
123 | bool "Trace boot initcalls" | |
1f5c2abb FW |
124 | depends on DEBUG_KERNEL |
125 | select TRACING | |
ea31e72d | 126 | select CONTEXT_SWITCH_TRACER |
1f5c2abb FW |
127 | help |
128 | This tracer helps developers to optimize boot times: it records | |
98d9c66a IM |
129 | the timings of the initcalls and traces key events and the identity |
130 | of tasks that can cause boot delays, such as context-switches. | |
131 | ||
132 | Its aim is to be parsed by the /scripts/bootgraph.pl tool to | |
133 | produce pretty graphics about boot inefficiencies, giving a visual | |
134 | representation of the delays during initcalls - but the raw | |
135 | /debug/tracing/trace text output is readable too. | |
136 | ||
137 | ( Note that tracing self tests can't be enabled if this tracer is | |
138 | selected, because the self-tests are an initcall as well and that | |
139 | would invalidate the boot trace. ) | |
1f5c2abb | 140 | |
e5a81b62 SR |
141 | config STACK_TRACER |
142 | bool "Trace max stack" | |
606576ce | 143 | depends on HAVE_FUNCTION_TRACER |
2ff01c6a | 144 | depends on DEBUG_KERNEL |
606576ce | 145 | select FUNCTION_TRACER |
e5a81b62 SR |
146 | select STACKTRACE |
147 | help | |
4519d9e5 IM |
148 | This special tracer records the maximum stack footprint of the |
149 | kernel and displays it in debugfs/tracing/stack_trace. | |
150 | ||
151 | This tracer works by hooking into every function call that the | |
152 | kernel executes, and keeping a maximum stack depth value and | |
153 | stack-trace saved. Because this logic has to execute in every | |
154 | kernel function, all the time, this option can slow down the | |
155 | kernel measurably and is generally intended for kernel | |
156 | developers only. | |
157 | ||
158 | Say N if unsure. | |
e5a81b62 | 159 | |
3d083395 SR |
160 | config DYNAMIC_FTRACE |
161 | bool "enable/disable ftrace tracepoints dynamically" | |
606576ce | 162 | depends on FUNCTION_TRACER |
677aa9f7 | 163 | depends on HAVE_DYNAMIC_FTRACE |
d3ee6d99 | 164 | depends on DEBUG_KERNEL |
3d083395 SR |
165 | default y |
166 | help | |
167 | This option will modify all the calls to ftrace dynamically | |
168 | (will patch them out of the binary image and replaces them | |
169 | with a No-Op instruction) as they are called. A table is | |
170 | created to dynamically enable them again. | |
171 | ||
606576ce | 172 | This way a CONFIG_FUNCTION_TRACER kernel is slightly larger, but otherwise |
3d083395 SR |
173 | has native performance as long as no tracing is active. |
174 | ||
175 | The changes to the code are done by a kernel thread that | |
176 | wakes up once a second and checks to see if any ftrace calls | |
177 | were made. If so, it runs stop_machine (stops all CPUS) | |
178 | and modifies the code to jump over the call to ftrace. | |
60a11774 | 179 | |
8da3821b SR |
180 | config FTRACE_MCOUNT_RECORD |
181 | def_bool y | |
182 | depends on DYNAMIC_FTRACE | |
183 | depends on HAVE_FTRACE_MCOUNT_RECORD | |
184 | ||
60a11774 SR |
185 | config FTRACE_SELFTEST |
186 | bool | |
187 | ||
188 | config FTRACE_STARTUP_TEST | |
189 | bool "Perform a startup test on ftrace" | |
3ce2b920 | 190 | depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER |
60a11774 SR |
191 | select FTRACE_SELFTEST |
192 | help | |
193 | This option performs a series of startup tests on ftrace. On bootup | |
194 | a series of tests are made to verify that the tracer is | |
195 | functioning properly. It will do tests on all the configured | |
196 | tracers of ftrace. | |
17d80fd0 PZ |
197 | |
198 | endmenu |